Liquid detergents for automatic dishwashers have been commercialized since the mid 1980s. These detergents have overcome many problems encountered with automatic dishwashing detergent powders. For example, powder detergents lose solubility on aging, cake in the dispenser cup and create dusting generated by fine particles when dispensed.
However, automatic dishwashing liquids, (ADLs) present a challenge to detergent artisans in terms of structuring the compositions to provide consumer acceptable viscosities. For example, clays have historically been used, however, such structurants are deficient.
Further, cross-linked acrylic polymers having a molecular weight of greater than about 1,000,000 have also been used as structurants, however, such polymers may be quite expensive and not cost effective, as well as being non-biodegradable.
Structurants which are biodegradable, such as naturally occurring polysaccharide gums or biopolymeric gums produced by microbial fermentation of sugars have been used as preferred alternatives to the above discussed structurants. Such gums are, however, highly sensitive to chlorine agents and cannot be used in liquid compositions unless the chlorine agent can be encapsulated (see Fox et al., U.S. Pat. No. 4,260,528).
Even in combination with encapsulated bleach, such biodegradable structurants were observed to degrade by residual bleach or by the hypochlorite leaking from the encapsulates. In these prior art compositions, the structurants are even more chlorine sensitive than enzymes present in the compositions.